Washington -- Sen. Mary Landrieu, D-La., broke from fellow Democrats on Thursday and voted against a party leadership proposal to replace $85 billion in across the board budget cuts with a combination of targeted cuts and higher tax revenues. It fell nine votes short of the 60 needed for passage. The final tally was 51-49.

Sens. Mary Landrieu and David Vitter cast votes Thursday on sequester bills. Both failed, virtually assuring that $85 billion in across-the-board cuts will begin to take effect on Friday. Scott Threlkeld, The Times-Picayune archive

Also failing was a Republican plan to give President Barack Obama flexibility to decide how to implement the $85 billion in spending reductions, due to take effect on Friday. The GOP plan fell by a vote of 38-62.

The votes all but guarantee that the sequester and its automatic spending cuts will go forward as scheduled on Friday, despite warnings by President Obama that it will hurt the U.S. economy and leave both military and domestic agencies short of funding for needed services.

The president and congressional leaders are meeting at the White House Friday to discuss the sequester, but there's little optimism an agreement can be reached to avert it.

Landrieu voted against both the Democratic and Republican proposals. She objected to a cut of $27.5 billion in direct farm subsidies over 10 years incorporated in the Democratic plan - a cut the Louisiana Farm Bureau said would hurt the state's rice farmers.

"I am strongly in favor of a balanced approach to fix our debt and deficit problems in a way that has the least negative effect on the promising economic recovery underway across the country," Landrieu said. "However, I could not vote for either proposal today - one of which refused to raise any additional revenue and the other that would disproportionally take the cut out of agriculture."

"Louisiana farmers and rural communities are a very important component of our economy at home and I do not think it is fair to single them out in this way. I remain committed to a 10-year balanced approach to fix our problems, but neither plan presented today would have done so."

Sen. David Vitter, R-La., joined Republicans in voting against the Democratic sequester alternative, but supported the GOP proposal to give the president and federal agencies flexibility on how to implement the cuts.

On Wednesday, Vitter said "blunt" across-the-board cuts under the sequester are not the best way to reduce the budget, and that agencies should be allowed to develop alternatives that would save the same amount of money without cutting important government programs, most notably key defense operations. But he said it was important that Congress be able to review the White House actions.